I should probably go to the Apache-specific site for this, but I thought
I'd ask here in case anyone else has seen the like.

We have Apache running as a Subversion server on a Solaris 10 box. It's
all working a treat.

Now, we have the server explicitly only talking SVN over https, and we
use that exclusively. The http I/F only give a dummy "it's working" page.

Every so often¹, SVN stops responding; all [https, not just svn]
requests just hang. I accidentally discovered, while trying various
diagnoses, that requesting said dummy page over http unfreezes the server.

This has happened a number of times now, and every time without fail,
going to http://oursvnserver/ to get the dummy page immediately unfreezes
all current requests. I see no errors in the Apache log for the times when
this occurs.

Has anyone else seen anything like this?

¹ - we seem to have come up with a near-failure case that causes this almost
every time, which I'll post about separately, but I'm not sure it's
relevant. (It's when trying to co a dir. with 5000+ files in onto a Windows
box whose virus scanner goes berserk trying to monitor the activity).